Multi-tone photoelectric musical instrument



Oct. 8, 1968 J. L. HEINZL MULTI-TQNE PHOTOELECTRIC MUSICAL INSTRUMENT 5 Sheets-Sheet 1 Filed July 8, 1965 FIG. 1

bct.8,1968 I i J. L. HEINZL 3,405,222

MULTI-TONE PHOTOELECTRIC MUSICAL INSTRUMENT Filed July 8, 1965 5 Sheets-Sheet 2 Oct.

Filed July 8, 1965 5 Sheets-Sheet 5 mi A I lfl 8 ,1

g! f I Z 0 1 I FIG. 5 A

FIG. 7 71 1/5100? Oct. 8, 1968 J. 1.. HEINZL 3,

MULTI-TONE PHOTOELECTRIC MUSICAL INSTRUMENT I Filed July 2, 1965 1 1 5 Sheets-Sheet 4 FIG. 15

Oct. 8, 1968 J. HEINZL MULTI-IONE PHOTOELECTRIC MUSICAL INSTRUMENT Filed July 8, 1965 5 Sheets-Sheet 5 FIG 17 141 12 5 1&2 1: 142 1:? 1 128 145 139 FIG. 70

United States Patent MULTI-TONE PHOTOELECTRIC MUSICAL l INSTRUMENT Joachim L. Heinzl, 24 Tulbeckstrasse,

I 8 Munich 12, Germany Filed July 8, 1965, Ser..No. 470,449 Claims priority, application Ggrmany, July 27, 1964,

4 Claims. oi. s4 1.1s

This invention relates to electrical musical instruments, and'in particular to photoelectrical musical instruments having stationary tone-representation repetitively scanned by moving light beams.

An object of this invention is to provide an electrical musical instrument for producing complex tones, with amplitudes and differences in phase of harmonic components that'may vary as the tone proceeds, for simulating other musical instruments and sounds more faithfully or for producing musical tones unknown heretofore.

Another object of the invention is to provide an easily manufactured, keyboard-operated electrical musical instrument, for producing the scale of musical tones by means of one or more interchangeable stationary modulation patterns simultaneously or successively, said modulation patterns representing independently of the pitch amplitudes and differences in phase of the harmonic components and their variations with time.

Still another object of the invention is to provide an electrical musical instrument for producing musical tones with vibrato effects that depend not only upon periodic Variations of frequency or amplitude, but also upon periodic variations of wave form. t

' Other objects and advantages of the invention will appear as the description proceeds.

Briefly stated, in accordance'with one aspect of this invention a photoelectricmusical instrument, has an interchangeable, stationary modulation pattern, representing by'mea'ns of different light transmitting qualities, inde-' pendent of the'pitch, amplitudes and differences in phase of the harmonic components of'a'complex tone in one direction (wt) and their variation with time in another direction (z), and a inulti-tone scanning device scanning the modulation pattern simultaneously with a plurality of scanning beams, one of them for each tone of the musical scale, and each of them scanning the modulation pattern periodically with the fundamental frequency of the corresponding note in one direction (wt) and each of them being deflectable in the other direction (z) by means of a corresponding beam deflection appliance. Each of said beam deflection appliances deflecting in its normal rest position the scanning beams to the unmodulated part of the modulation pattern, but set in action, superimposing the periodical scanning motion of the scanning beams in one direction (wt) with a scanning motion in the other direction (z), so that the entire modulation pattern is gradually scanned. This multi-tone scanning device and the modulation pattern are optically arranged between stationary light sources and a stationary photoelectric transducer receiving the modulated light and converting it into electric signals, which are used to produce sound waves.

In accordance with another aspect of this invention a photoelectric musical instrument has a projection screen on which the images of a variable number of modulation patterns can be formed and superimposed optically, and a multi-tone scanning device scanning this projection screen.

In accordance with still another object a photoelectric musical instrument has a modulation pattern, which is moved periodically relative to the path of rays of the multi-tone scanning device scanning this modulation pattern.

In accordance with the same object a photoelectric musical instrument has an interchangeable, multicolored modulation pattern and a multi-tone scanning device scanning this modulation pattern with scanning light beams of periodically varying color composition.

.The invention will be better understood from the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings:

FIG. 1 is a simplified schematic and circuit diagram of a photoelectrical musical instrument embodying principles of the invention;

FIG. 2 is a view of an example of a modulation pattern;

FIG. 3 is a diagram illustrating the variations with time of the amplitudes of the harmonic components of the complex tone represented by the modulation pattern shown in FIG. 2;

FIG. 4 is a diagram illustrating the variations with time of the zero phase angles of the harmonic components of the complex tone represented by the modulation pattern shown in FIG. 2;

FIG. 5 is a diagram illustrating an example of the time variation of the scanning motionin direction z;

FIG. 6 is a representation of the paths wayof scanning light beams across the modulation pattern as resulting from superposition of the scanning motion in direction of z as illustrated in FIG. 5 with a periodical scanning motion in direction wt; 7

FIG. 7 is a diagram illustrating the variations with time of the instantaneous frequencies of the harmonic components as resulting from the scanning according to FIG. 6 of the modulation pattern shown in FIG. 2;

FIG. 8 is a schematic view, partly in section showing a beam deflection appliance; 7

FIG. 9 is a schematic view of a modified of beam deflection appliance;

FIG. 10 is a schematic plan view, partly in section showing a scanning device for an organ-type musical instrument containing two manual keyboards and one pedal clavier;

FIG. 11 is a schematic illustration of apparatus for. rotating the scanning disks of the musical instrument, shown in FIG. 10;

FIG. 12 is a schematic plan view showing an optical system for superimposing modulation patterns;

FIG. 13 is a schematic illustration of apparatus for periodical movement for modulation pattern;

FIG. 14 is a schematic view of revolving color disk for varying the color of scanning light beams periodically;

FIG. 15 is a schematic illustration of the arrangement of revolving color disk shown in FIG. 14 in the scanning device.

Reference is now made to FIG. 1 of the drawings, which is -a schematic diagram of a photoelectrical musical instrument embodying principles of the invention. In FIG. 1 only one scanning disk perforated by only three rows of scanning apertures is shown, but it will be understood that a number of such scanning disks perforated by a plurality of such rows will be provided in actual practice for producing a plurality of tones of different pitch. A scanning disk 1, which may be a circular, generally opaque disk perforated by concentric rows 2, 3, and 4 of scanning apertures, is rotated at constant speed by a motor 5. A light source, such as the electric lamp 6, illuminates by means of focusing lenses 7 a part of the scanning disk 1. The images of the illuminated, moving scanning apertures (slits or the like) are projected upon modulation pattern 9 by objective 8 by means of the pivoted mirrors 12,

i l '1 'fi e aa fl qa .a rli ncss 3? 123W. 20. "As the scanning disk 1 rotates, the projected images scanning motionis' superimposed on the scanning'motion 20, supplying it with electrical power from any suitable source, such as battery 21 as long as the corresponding switch is closed-Various modifications of deflection appliances will be described in connection with FIGS. 8 and 9 of the drawings' y a Light transmitted through the modulation pattern reaches through focusing lens the cathode of a photoelectric transducer 26, preferably a phototube or a photomultiplier-tube, which converts modulated light' into an electric signal. Electric power is supplied to phototube 26 by any suitable means, such as battery 27. The electric signal produced by phototube 26 is amplified by an amplifier 28. A signal modifier 29 may be provided for adding various musical effects, such as reverberation, choral effects, vibrato and tremolo effects and the like. After that the electric signal is supplied to one or more loudspeakers 30, which convert the electric signal into sound waves.

One ormore other light sources 6,.focusing lenses 7', objectivs 8, deflection appliances '18, 19, and 20, switches 22', 23, and 24', modulationpatterns 9", focusing the direct-current component.

lenses 25, and phototubes 26 may bearrangedacross the I circumference of the scanning disk 1, as shown in FIG. 1.

In order to avoid the amount of hum produced by operating the lamps with alternating current, they may be supplied with direct current by any suitable means, such as battery 31. Low voltage lamps supplied with low voltage alternating current may be used as well. Switches 32 and 32' are provided to set in action lamp 6 and 6 A complex tone in which amplitudes and zero phase angles of the harmonic components (partials) are function of the time, may be represented by the equation:

p-1 0= n( sin pn( Therein p means the instantaneous sound pressure, Po the "atmospheric pressure, n the ordinal number of partial, A the amplitude of partial n, w the circular frequency, the zero phase angle of partial n, and t the time. A modulation pattern is a plane representation (a photo graphic slide or the like) of all values of -p-p of this equation for one complex tone independent of the pitch. In conformity with the scanning motions there are fixed two axes normal to each other on the modulation pattern, one standing for the angle wt from 0 to 2w andthe other for z=z(t). To each point in this plane (wt-2(0) a value of EA, sin (nwt-i-zp is defined, if A =A (t), Pn Pn( and or n n( and Pn=Pn( is known. This value is represented by the light transmitting qualities of the modulation pattern at that corresponding point. The ranges of different light transmittingqualities of the modulation pattern are realized either by different grey-scale values or byrastering or even by colors. 1

The circular frequency w is represented as a time-independent variable on the modulation pattern. So it is possible to select pitch by means of the frequency of periodical scanning in direction wt, independent of scan na p tt q di e v .z ,inde ende t the etro:

duction' speed of the complex tone,"witho'utlosiriig'control of amplitudes and zero phase angles of partials. So the whole scale of musical tones can be produced from a single modulation pattern, I

Reference is now made tQEIG S. 2, 3, and .4 of the drawings, which illustrates an example of 'a'modulation pattern. H l

FIG. 2 represents a modulation pattern, which is calculated to produce, if scanned periodically in direction of wt at-a consta'nt value of z, a signal containing the values of amplitudes and zero phase "angles of partials as defined for the same value of zas in FIGS. 3 and 4. The ranges of different light transmitting qualities on the modulation pattern are realized by rastering;'which ras'tering is so selected, that the rastering *fr'eduency and its integral multiples owing to theextentsof scanning light beamsin direction wt do not enter into the resulting signal. It will be understood, that in real practice more detailed rasterings of different structure may be used. "Thehatched region 33 on the modulation pattern is opaque, the reniaining parts 34are fully transparent. To the left "of the broken line 35 the unmodulated 'partof the modulation pattern is situated.

"In FIG. 3' the ordinates stand for the'amplitudesof partials as plotted against 2:. Curves 36, 37, and 3-8 represent the amplitudes of partials, 1, 2, and 3, the broken line 39 represents the amplitude of zeroth partial, that is 'In' FIG. 4 the ordinates stand for the Zero! phase angles as plotted against z. Curves 40, 41, and4 2"represent the zero phase angles of partials 1, 2', and 3. The zero phase angle of zeroth partial as represented by the broken line '43 is determined by Equation 1.

- The time variations of the motion in direction z according to z=z(t) is controlled by the beam deflection appliances. Scanning motion in direction z is only necessary as long as amplitudes and zero phase angles of the partials are to be altered. If they reach constant values, further motion in direction of z is superfluous. If amplitudes and zero phase angles of the partials vary periodically,they may be produced by periodical scanning motion in direction of 1 as described in connection with FIG. 13 of the drawings.

"Reference is now made to'FIGS. 5, 6, and 7 of the drawings, which illustrate a practical example for Scanning a modulation pattern. y

In FIG. 5 the ordinates of curve 44 stand for the time (1 -as plotted against 2.

' In FIG. 6 curves 46 represent the path of the scanning light beams across the modulation pattern, as resulting from the scanning motion in direction 1 as illustrated in FIG. 5 together with a periodical scanning motion in tones of percussion direction wt. If, for example, the modulation pattern shown in FIG. 2 is scanned according to FIG. 6, no signal is produced by scanning in the rest position along line 47, because in this range the modulation pattern is opaque. By scanning along line 48 the steady-state portion of a complex tone,.which can be prolonged at random is produced. By scanning between lines 47 and 48 an attack transient portion whose time-variations of amplitudes and zero phase angles of partials as plotted in FIGS. 3 and 4 is produced. Between lines 47 and 48, there might also be represented attack and decay transients of complex or plucking instruments or other sounds. i v

i The influence of the alternations of the zerophase angles of partials of a complex tone will be recognized by considering the variations with time of instantaneous frequencies. The instantaneous frequency f* of a varying sinusoidal oscillation is the differential quotient of phase angle with respect to time.

On the other hand the frequencies f of partials in the steady-state portion of the tone are:

By relating the instantaneous frequency f,,* to the steady-state frequency i the frequency ratio j /f is formed:

In FIG. 7 the variations with time'of frequency ratio f */f of the partials 1, 2, and 3 are represented by curves 49, 50, and 51 as produced by scanning according to FIG. 6 the modulation pattern shown in FIG. 2. As FIG. 7 shows, it is possible to produce, by means of modulation pattern, such as the modulation pattern shown in FIG. 2, even anharmonic components of complex tones, as they often occur in the attack transient effects of wind-instruments. I

Reference is now made to FIG. 8 of the drawings, which illustrates a beam deflection appliance as used in FIG. 1 under reference number 18, 19, 20, and 18', 19', 20'. A mirror 12 pivots about bearing 15 which is normal to the plane of drawing, by means of link53. Spring 52 tends to rotate link 53 in clockwise direction and thus keeps feeler 54 in contact with the profile 55. Profile 55 is connected through piston rod 56 with piston 57 moving within cylinder 58 filled with damping fluid. In the lower part of cylinder 58 an electromagnet 59 is provided. As long as current coil 60 of electromagnet 59 is not supplied with electric power, piston 57 is kept at the top of cylinder 58 in its normal rest position by means of compression spring 61 arranged between profile 55 and lid 62 of cylinder 58. Assoon as current coil 60 is supplied with electric power, the soft iron parts of piston 57 are attracted by iron-core 63 of electromagnet 59. As, however, during the downward stroke of piston 57 damping fluid is forced through the narrow ring slot 65 between piston 57 and cylinder 58, and the downward motion of piston 57 is considerably damped. As soon as the supply of electric power for current coil 60 ceases, piston 57 is moved back to its rest position ,by compression spring 61. The motion of piston 57 and profile 55 are transformed into pivoting motion of mirror 12 by means of feeler 54. The desired time variation of the scanning motion in direction z may be accomplished by means of appropriateprofile design. It will be understood, that magnetic motive force may be replaced by any suitable means, such as inductive motive force or the like, and liquid dampingby any suitable means, such as eddy-current damping or the like. Cylinder 58may be fixed on base plate 68 by means of threaded soft ironcore bolt 63, nut 66 and locking screw 67, side by side with other similar beam deflection appliances.

In addition there are screen mechanisms fixed on base plate 68, such as 77. The chief function .of screen 69 is to interrupt the scanning light beams during the return movement of mirror 12. By means of link 70, screen 69 is pivoted about bearing 71. Spring 72 tends to rotate link 70 in anticlockwise direction towards stop 73 in its normal rest position. As soon as electromagnet 74 is supplied with electric power the soft iron part 75 of link 70 is attracted towards the iron-core 76 of electromagnet 74, so that the light beams are no longer interrupted. As soon as electric power supply ceases, spring 72 moves screen 69 back into its normal rest position. The current coils of electromagnets 74 and 59 are controlled by the same switch such as switch 22, 23, 24, 22, 23, and 24' inFIG. l, and may be connected in series or in parallel.

Reference is now made'to FIG. 9, representing a simplified beam deflection appliance. By means of link 78 mirror 12 is pivoted about bearing 15', which is normal to the plane of drawing. Spring 79 tends to rotate member 78 in anticlockwise direction so that in its normal rest position the soft iron part 80 lies against stop 81. As soon as the current coil of electromagnet 82 is supplied with electric power, the soft iron part is attracted towards iron-core 83 of electromagnet 82 and thereby mirror 12 is swung out of its rest position. The beam deflection appliance shown in FIG. 9 is only capable for producing complex tones with short attack transient portions'and arbitrarily long steady-state portions. Also the scanning light beams are not interrupted during the return movement, but for same types of tones this is of little consequence.

Reference is now made to FIG. 10 of the drawings, which is a schematic plan view, partly in section showing a scanning device for an organ-type photoelectric musical instrument, containing two manual keyboards and one pedal clavier. With regard to FIG. 1 the sectional area through the path of rays is revolved by deg. in FIG. 10 and light sources and photoelectric transducer are in interchanged optical position. Six scanning disks 90 through inclusive, equivalent to scanning disk 1 in FIG. 1 are rotated by a motor 96. The six scanning disks are geometrically identical, each perforated by twelve concentric rows of scanning apertures, adequate for producing one octave of tones of the musical scale, but rotated at different speeds. Apparatus for rotating the scanning disks 90 through 95 will be described in connection with FIG. 11. In deflection units such as are represented schematically by reference number 97 through 102 and 98' through 101, there are assembled in each of them twelve beam deflection appliances such as 18, 19, 20 or 19', 19, 20 in FIG. 1. To scanning disks 91, 92, 93, and 94 two objectives, deflection units etc. are provided, one of them being hidden in FIG. 10. The reference numbers of these hidden parts are marked by in accordance with FIG. 1. Light sources 109, and 109' illuminate modulation patterns 113, 114, and 113' by means of focusing lenses 111, 112 and 111. Objectives 103 through 108 and 104' through 107 (similar to objectives 8 and 8 in FIG. 1), project a section of the illuminated modulation pattern, selected by the beam deflection appliance on the concentric rows of slits in the scanning disk 90 through 95. The modulated light transmitted through the scanning disks reaches the cathodes of photoelectric transducers 127 respectively 127 by means of focusing lenses 114 through 120 and 115 through 118' and 120 and mirrors 121 through 126 and 122 through 125' and is converted into electric signals. Deflection units 97 through 100 and 98' through 101' for scanning modulation patterns 113 and 113' may be connected with two different manual keyboards, and deflection units 101 and 102 for scanning modulation pattern 114 may be connected with a pedal clavier.

Reference 'is now made to FIG. 11 which shows an arrangement for continuously rotating the scanning disks. Each scanning disk is connected to a driving shaft, such a shaft 128, carrying two different-sized driving wheels, the larger one (such as driving wheel 129 and 130 having double the diameter of the smaller one (such as driving wheel 131 etc.). Shaft 132 of motor 96 carries a driving wheel 133 as well. In addition, a number of frictional wheels 134 through 139 guided by links 140 through 145, forced against the driving wheels by springs 146 through 151 are provided, so that scanning disk 91 is rotated continuously at half the speed of disk 90, disk 92 at half the speed of disk 91 and so on (except disk 95, which is rotated at the same speed as disk 93). The scanning disks being geometrically identical, each of them is capable of producing by means of their different speeds of rotation the notes of another octave. It will be understood that the arrangement of the scanning devices of a photoelectric musical instrument given in FIG. 10 and 11 is only one of many possible combinations of several scanning disks, modulation patterns, and deflection units. Reference is'now'inade to FIG. 12 'of the' drawings, showing an optical system for superimposing modulation patterns in order to scan them simultaneously with the same scanning device. If for example modulation pattern 113, light source 109, and focusing lenses 111 in FIG. are replaced by focusing screen 158, on which several modulation patterns, such as 159, 160, 161 or may be projected by objectives such as 162, 163, 164 focusing screen'158 may be scanned by the scanning device shown in FIG. 10 in the way as previously modula tion pattern 113. Lamps such as 165, 166 and 167 illuminating modulation patterns, such as 159, 160, and 161 by means of focusing lenses 168, 169, and 170, can be switched on individually. Thus the modulation patterns to be scanned can be selected and combined as organ stops are pulled.

Instead of focusing screen (such as 158) any projecting screen may be used. An analogous optical system may be provided in the scanning device shown in FIG. 1 (light source and photoelectrical transducer in interchanged posi-v tion with respect to FIG. 10), if projection lamps (165, 166 and 167) are replaced by photoelectric transducers.

Vibrato effects that depend not only upon periodic variations of frequency or over-all amplitudes, but also upon periodic variations of wave form, may be'interpreted as periodic variations of amplitudes and zero phase angles of partials in accordance with Equation 1 and as mentioned above, may be realized by scanning modulation pattern with superimposed periodic scanning motions in direction z. The same effect is produced by periodically moving the modulation pattern relative to the path of rays in direction 2. On the other hand periodic moving of modulation pattern in direction wt produces simple periodic variations of frequency.

Reference is now made to FIG. 13 illustrating apparatus for moving modulation pattern periodically in direction z as well as in direction wt. Links 171 through 175 assure parallel guidance of support 176 carrying the modulation pattern. Two disk cams 177 and 178 are continuously rotated by a motor 179 and in accordance with their shape specify time variations of the motion of modulation pattern, in direction z and wt. A spring 180' forces support 176 against cams 177 and 178.

Another means suitable for representing characteristics of complex tones on modulation pattern is color. If amulticolored modulation pattern (as for example a color slide) is scanned by different colored light beams, different signals are produced. This effect can be used to modify a complex tone according to its pitch by means of a multicolored modulation pattern and a number of stationary color filters provided in the scanning device. By periodically varying the color composition of scanning light beam vibrato effects depending on periodic variations of wave form can be produced.

Reference is now made to FIGS. 14 and showing a revolving color disk and its arrangement for periodically varying the color composition of the scanning light beams. Revolving color disk 181 consists of many sectors of different colored filter glasses 183 through 188 and is continuously rotated round bearing 182 by motor 189. The revolving color disk 181 is preferably arranged in the path of rays near the projection objective 190 (such as for example objective 8 in FIG. 1 or objectives 103, 104 in FIG. 10).

The advance in the art offered by this invention is the possibility to produce in a photoelectric musical instrument, by means of a single interchangeable modulation pattern, the whole scale of complex musical tones, whose amplitudes of the partials, and their time variations are specified by this one modulation pattern. The additional possibility of specifying time variations of zero phase angles of partials in the same modulation pattern as well as the possibility of producing anharmonic components and complicated vibrato effects, closes a gap in the art. The means of attaining all these effects by means of one modulation pattern and a multi-tone scanning device is essentially less complicated than any means known heretofore. 7

It should be understood that this invention in its broader aspects is not limited to specific embodiments herein illustrated and described, and that the following claims are intended to cover all changes and modifications thatdo,

part in another direction (2) and a multi-tone scanning device comprising a number of scanning disks, objectives and other optical means, a plurality of beam deflection appliances, light sources and photoelectric transducer means said scanning disks continuously rotated at constant speed being generally opaque, however perforated by a plurality of concentric rowsof equidistant scanning apertures, one of said rows for each note of the musical scale, said objectives forming by means of said'beam deflection appliances optical images of single scanning apertures ofeach of the said rows on a section of said modulation pattern and analogously of the same section of the modulation pattern on saidrows, said single scanning apertures scanning said modulation pattern periodically with the fundamental frequency of the corresponding. complex tone in said one direction.(wt) and said beam deflection appliances being'optically arranged between said objectives and said modulation pattern, each of them corresponding to one of said rows and controlling individually the scanning motion in said other direction (2.) and thus determining begin, duration, and time variations of a complex tone, said scanning disks, said objectives, said beam deflection appliances, and said modulation pattern being optically arranged between said stationary light sources and said photoelectric transducer means, receiving the modulated light and converting it into electric signals, which are used to produce soundwaves.

2. In a photoelectric musical instrument a projection screen on which the images of variable number of modulation patterns can be formed and superimposed optically and a multi-tone scanning device, as claimed in claim 1', scanning the projection screen instead of a single modulation pattern.

. 3. In a photoelectric musical instrument an interchangeablemodulation pattern and a multi-tone scanning device as in claim'l, additionally comprising apparatus for moving said modulation pattern periodically relative to the path of rays of said multi-tone scanning device, for producing vibrato effects. 1

4. In a photoelectric musical instrument an interchangeable, stationarymodulation pattern and a multi-tone scanning device as claimed in claim 1, said modulation pattern being multi-colored and said multi-tone scanning device additionally comprising a revolving color disk, varying the color composition of the scanning light beams periodically, for producing vibrato effects. Y

References Cited.

UNITED STATES PATENTS ARTHUR GAUSS, Primary Examiner.

D. D. Forrer, Assistant Examiner. 

1. IN A PHOTOELECTRIC MUSICAL INSTRUMENT AN INTERCHANGEABLE STATIONARY MODULATION PATTERN REPRESENTING BY MEANS OF DIFFERENT LIGHT TRANSMITTING QUALITIES, INDEPENDENT OF THE PITCH, AMPLITUDES AND DIFFERENCES IN PHASE OF THE HARMONIC COMPONENTS OF A COMPLEX TONE IN ONE DIRECTION (WT) AND THEIR VARIATIONS WITH TIME AND AN UNMODULATED PART IN ANOTHER DIRECTION (Z) AND A MULTI-TONE SCANNING DEVICE COMPRISING A NUMBER OF SCANNING DISKS, OBJECTIVES AND OTHER OPTICAL MEANS, A PLURALITY OF BEAM DEFLECTION APPLIANCES, LIGHT SOURCES AND PHOTOELECTRIC TRANSDUCER MEANS SAID SCANNING DISKS CONTINUOUSLY ROTATED AT CONSTANT SPEED BEING GENERALLY OPAQUE, HOWEVER PERFORATED BY A PLURALITY OF CONCENTRIC ROWS OF EQUIDISTANT SCANNING APERTURES, ONE OF SAID ROWS FOR EACH NOTE OF THE MUSICAL SCALE, SAID OBJECTIVES FORMING BY MEANS OF SAID BEAM DEFLECTION APPLIANCES OPTICAL IMAGES OF SINGLE SCANNING APERTURE OF EACH OF THE SAID ROWS ON A SECTION OF SAID MODULATION PATTERN AND ANALOGOUSLY OF THE SAME SECTION OF THE MODULATION PATTERN ON SAID ROWS, SAID SINGLE SCANNING APERTURES SCANNING SAID MODULATION PATTERN PERIODICALLY WITH THE FUNDAMENTAL FREQUENCY OF THE CORRESPONDING COMPLEX TONE IN SAID ONE DIRECTION (WT) AND SAID BEAM DEFLECTION APPLIANCES BEING OPTICALLY ARRANGED BETWEEN SAID OBJECTIVES AND SAID MODULATION PATTERN, EACH OF THEM CORRESPONDING TO ONE OF SAID ROWS AND CONTROLLING INDIVID- 